Carbohydrate - continued

The search for new methods of synthesis of halogenated carbohydrates continues to be an active area of investigation. The compounds are of utility as synthetic intermediates, and many of them are of intrinsic value in biochemistry and pharmacology. In the present Chapter methods for the synthesis of deoxyfluoro sugars and glycosyl fluorides are discussed. 

The jejunum is the middle portion of the small intestine in between the duodenum and the ileum. Digestion of protein and carbohydrates continues after receiving pancreatic juice and bile in the duodenum, this portion of the small intestine generally has less contraction than the duodenum and is preferred for in vivo drug absorption studies... 

Biological chemistry and its needs increasingly dominate the phosphorus(v) acids area and the majority of novel results relate to compounds derived from phosphonic and phosphinic, rather than phosphoric acids. Numbers of studies of compounds related to inositol and to carbohydrates continue to appear, although few contain truly novel results. Phosphorus-containing analogues of amino acids... 

The analysis of carbohydrates continues to be of considerable importance in the biological sciences. The diversity of structure and function of carbohydrates in organisms contributes to the difficulty of analysis of these materials. There exist a number of techniques for the analysis of carbohydrates, but no single technique has universal applicability. For the identification of carbohydrates, trimethylsilyl ethers are widely used in GC/MS. Veness and Evans " showed that GC/FTIR can also be used, with some advantages, for this purpose. A selection of 42 monosaccharides and related compounds were examined and, in each case, unique spectra were obtained for the differing compounds and their isomeric forms, allowing unambiguous identification. These results indicate that GC/FTIR of trimethylsilyl ethers of monosaccharides is a useful analytical technique for their identification. The resultant spectra are unique, easy to interpret, and stereo-isomeric forms are readily differentiated. 

TABLE 23.2 Familiar Reaction Types of Carbohydrates continued... 

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